Electrical terminal prong



July 4, 1939. vm 2,164,766

ELECTRICAL TERMINAL PRORG Filed Feb. 1:5, 195s ATTORNEY.

Patented July 4, 1 939 J UNITED STATES 2,164,766 ELECTRICAL TERMINALPRONG Arthur M. Draving, Philadelphia, Pa., asslgnor to Hugh H. Eby,Inc., Philadelphia, Pa.

Application February 13, 1936, Serial No. 63,744

3 Claims.

My invention relates to improvements in electrical drawn metal terminalprongs for electrical plug-in-devices.

Prongs of this type, with which I am familiar,

have been made either-of solid metal, turned and drilled and which wascostly, or formed of drawn seamless metal requiring many operations toproduce. Still another type of prong was constructed of rolled sheetmetal (rolled up from same) having one lengthwise seam. Usually,however, with this type the outer surface was not uniform, especiallynear the rounded end. Heretofore all known types of terminal prongs weremade with a crimped or beaded shoulder for seating or limiting insertionof the prong in an insulating base.

One purpose of my invention is to provide a drawn metal terminal prongof uniform shape and maximum strength at low cost.

A further purpose is to provide a drawn metal terminal prong formed fromstrip metal in one operation.

A further purpose is to provide a drawn metal terminal prong incombination with an electrical plug-in-devlce. I

A further purpose is toprovide a drawn metal terminal prong having aslotted open end with the bottom edge of the slot serving as a limitingor abutting shoulder when mounted on an in- 543 sulating base.

A still further purpose is to provide sidewall extensions by means ofthe aforesaid slot in the open end of the prong to provide means forriveting, or eyeleting-over the prong end when mounted on an insulatingbase.

A stifl further purpose is to provide an insulating mounting base havingsuitably formed apertures to receive and hold a drawn metal prong.

With the foregoing and other objects in view 63 I have devised animproved terminal prong construction and method of fabricating same andmy invention lies in the structure a d'features hereinafter describedand claimed.

Referring to the drawing.

Fig. 1 shows a strip of metal prior to drawing with its ends notched to'form slot and. side wall extensions.

Fig. 2 shows a punch and a section through the die for forming a prongwith a sheet metal m strip shown in dotted lines thereon.

Fig. 3 shows a front elevation of a prong completely formed withsidewall extensions and having a slotted area at the open end.

Fig. 4 shows a top view of Fig. 3.

Fig. 5 shows a side elevation of a prong with straight sides.

Fig. 6 shows a fragment of an insulating base having an, aperture toreceive a prong.

Fig. '7 shows a front elevation of a, prong in- 5 serted in an aperturein the insulating base before peening over of side wall extensions, withthe base shown in section. I

Fig. 8 is the same as Fig. 7 except that th side wall extensions havebeen peened over'after 10 the riveting operation has been completed.

Fig. 9 shows a top view of a fragment of insulating base with the prongmounted therein and peened over as in Fig. 8.

Fig. 10 is a top View of the entire insulating 15 base showing the prongapertures and the prongs riveted in same.

Fig. 11 shows a side elevation of the base and prongs of Fig. 10.

Fig. 12 shows a section partially in elevation, of prongs and a vacuumtube base with a terminal wire soldered in 9. prong.

Referring to the drawing, like numerals refer to like parts in figuresin which they appear.

My invention is directed to a desirable form of electrical terminalprong and the economical formation thereof from strip metal andrequiring a simple notching and shearing operation prior to drawing, tominimize waste.

Electrical terminal prongs as has been men- 30 tioned have heretoforebeen manufactured with 9. rolled or pressed abutment shoulder formedintermediate their ends, which is costly in the manufacture of drawn orrolled seamed or seamless prongs. It is a feature of the invention toeliminate the shoulder without sacrificing strength or anchoringability. f

To economically produce a strong uniformly true seamed tubular prongwithout a head or an abutment shoulder, I provide strip metal of the mproper width so that when converted from the fiat strip Hi to thetubular prong ill: by bending it in the center about the end of thepunch, sides E3 and iii in Fig. 1 become theseams iii and i3. Notchingthe strip edges as at H and it (Fig. l) 45 thus reducing the width atthese points and form ing shoulders It; and i2 prior to bending, afterthe drawing operation, provide means abutment shoulders it and i2,between the transversely arcuate extension pieces H and E arising out ofthe straight wails of the tubular prong it (Figs. 3, and 4). Theinsulating base, Fig. 10, shows apertures through which prongs areinserted and rigidly fixed by peening over the side wall extensions Hand H as at. l8. One of the prong M receiving apertures I4, is shown inFig. 6, in which the insulating base is l6 and the aperture H is ofgenerally cylindrical form, slightly larger in diameter than the prongI! to permit insertion of the prong. Two projections or ears l5 and I5extending inwardly from the circumferential edge of the aperture l4engage slots 19 between extensions H and II of the fully opened end ofthe prong and prevent the prong from turning in the aforesaid base.After the prong has been inserted preparatory to peening, the abutmentshoulders I2 and I2 engage and seat against the under side of theaperture-projections i5 and I5, which thereby aligns the prong to extendtruly at right angles to the under side of the insulating base l6.

The side wall extensions II and I extend through and past the topsurface of the insulating base, as indicated in Fig. "I, and are peenedover outwardly as at I] (Fig. 8) thereby drawing abutment shoulder l2firmly against the under side 2| of the insulating base, producing arigid alignment between the longitudinally split rigid tubular prongsand the insulating base member.

In Fig. 12 I have shown an insulating base of a radio tube beingpre-apertured to receive and hold the drawn split tubular prongs. Theterminal .wires of the inner parts of the vacuum tubes, such as thefilament, grid and plate, are soldered to the prong by providing asuitable hole 20, in the rounded end of the prong so that the terminalwires may be inserted and the ends of same reach the substantiallyopened tip of the prong and are soldered to same by dipping the ends ofthe prongs in solder.

While I have described but a single embodiment of my invention in thedrawing and description, it is still possible to modify same withoutdeparting from the scope of the appended claims.

What is claimed as new is:

l. A plug-in device including an insulating base member provided with anaperture, the side Walls of the aperture being semi-circular andseparated each from the other by at least two inwardly extendingportions of the base member material,

and a terminal prong mounted in said aperture, the said prong includinga drawn metal tube having side wall seams, one end thereof beinggenerally rounded, the other end thereof being open, the open end beingslotted back in at least two places to accommodate the inwardlyextending portions of the base member material and the bottom of eachslot constituting an abutment shoulder adapted to contact the undersurface of the said inwardly extending portions, the side wallextensions of the prong adjacent the slots passing through the aperture,fitting against the semicircular side walls thereof and being peenedover against the upper surface of the insulating base member, wherebythe prong is firmly held in place and is secured against rotation.

. 2. An electrical terminal prong which consists of a sheet metal stripdoubled upon itself to form a cylindrical element having an open end anda substantially rounded end, the side walls at the 'open end being cutback, respectively, from the seams to provide at least two oppositelydisposed semi-circular extensions, each extension having a peripheryless than half the periphery of the element.

3. An electrical terminal prong which consists of a sheet metal stripdoubled upon itself to form a cylindrical element having an open end anda substantially rounded end, the side walls at the open end being cutback, respectively, from the seams to provide a least two oppositelydisposed semi-circular extensions, each extension having a peripheryless than half the periphery of the element, in combination with anorificed, substantially planar insulating base, the orifice beingprovided with at least two oppositely disposed projections extendingtoward the axis thereof, the projections being disposed, respectively,in the slots defined by the side wall extensions of the prong to preventrotation thereof, the said extensions being peened over into contactwith the surface of the substantially planar element to lock the prongin position.

ARTHUR M. DRAVING.

